Prepare to Make Unreal Games with Unreal Engine – Installing and Setting Up - Learning Unreal Engine iOS Game Development - page 6

5. When you run the launcher, you will find many useful links to the forums, answer
hubs, and marketplace where you can find free projects among other things.
You can go to the library and select an engine version (the latest should be the
best; I'm running 4.3 while writing this topic, as it is the latest one and was just
released a few days ago) and start installing it. After you finish, you will see a
new section called Engine Slots , which holds all the engine versions you are run-
ning via the launcher.
6. Finally, you can run the engine!